Performance of 3-D Infinite Elements for High-Frequency Electromagnetic Fields

The infinite elements for edge based finite-element methods (FEMs) have been shown effective for open boundary problems. In the infinite elements, electromagnetic fields are expressed in terms of radially decaying basis functions. On the other hand, the perfect matched layer has widely been used for FEMs for high-frequency problems. In this paper, numerical performance of both methods is comparably discussed. The numerical experiments show that the former has higher computational efficiency.

I. Introduction

High-Frequency electromagnetic filed computations using the finite-difference time-domain (FDTD) method, finite-element method (FEM), and method of moment (MoM) have widely been performed [1], [2]. The MoM has an advantage to deal with the infinite region without introducing artificial open boundaries. However we must solve equations including a dense matrix for MoM analysis. The FDTD method can effectively solve large scale problems because it is an explicit method. If analysis model includes curved surfaces or structures whose scale is much smaller than the whole scale, the FDTD method needs a great number of unknowns because it employs cuboid cells.